The proposed research is a controlled, prospective study of U.S. adolescents exposed to pregnancy at an age when linear growth occurs. A total of 225 young primigravid adolescents (15 years or younger), 225 multigravid adolescents (currently 18 years or younger) with a first pregnancy at 15 or less and 450 multigravid and primigravid women, with age at first pregnancy of 18 or greater, will be enrolled during pregnancy and followed through delivery to 24 weeks postpartum. Subjects are matched by ethnicity and clinic payment status and stratified by age at first pregnancy and current gravidity. The research will characterize nutritional status during pregnancy and the postpartum (measured by anthropometry, dietary intakes and biochemical determination of zinc, folate, calcium and iron), determine if growth is associated with poorer nutritional status and determine if poorer nutritional status is associated with increased pregnancy complications (PIH) and poor pregnancy outcomes (pre-term delivery and low birthweight). Multigravid adolescents, with first pregnancy at an age when growth occurs, are included to study effects of early adolescent pregnancy on nutritional status and pregnancy outcomes in a subsequent adolescent pregnancy. Mature controls, unexposed to pregnancy during growth, are included for comparison. There are three principal hypotheses: (1) that linear growth during pregnancy and postpartum is associated with poorer nutritional status; (2) that poorer nutritional status in adolescents increases their risk of complications (PIH) and preterm delivery/low birthweight; and (3) that pregnancy risk factors with a nutritional component increase from one pregnancy to the next and increase risk of preterm delivery/low birthweight in subsequent pregnancies of multigravid adolescents.